It is well known that an antenna is the key element to transmit/receive (transceive) microwaves in wireless technology such as wireless communication and wireless data transfer, where the antenna converts electrical currents generated by a transmitter into microwaves and transmits the microwaves in free space. The antenna also captures microwaves and converts them into electrical currents, which are then processed by a receiver. As a result, the characteristics of the antenna deeply affect that of the wireless technology, and the antenna can be referred as the index to examine the quality of the wireless technology.
Currently, antennas of conventional use are required with specific dimensions, and only the antennas with the required dimension optimize the feeding and transceiving of wireless signals. Many of those skilled in the art, therefore, utilize a resonant circuit to resonant with the antenna in order to magnify the electrical current fed to and transceived by the antenna, so as to reduce the noise and enhance the gain of the antenna to upgrade the quality of the wireless technology.
Please refer to FIG. 1 that shows a conventional use of a resonant circuit applied to the antenna. As shown in the figure, an antenna 1 couples with a resonant circuit 2, which is composed of an inductance 21 and a capacitor 22, in order to magnify the electrical current fed to and transceived by the antenna 1. As the antenna element 1 transceives the wireless signal of the predetermined radiation frequency and generates an induction voltage V1, the inductance 21 and the capacitor 22 each generates a coupled induction voltage V2 and a capacitance therebetween. As a consequence, the inductance 21 and the capacitor 22 form a resonance with the antenna element.
Although some of the conventionally used electronic devices with antennas in the market are accompanied with resonant circuits to upgrade the quality of the transceiving of the wireless signals, the resonant circuits are in fact individually manufactured and then arranged in the electronic devices and electronically connected to the antenna. Such manufacturing is not only troublesome bust also increases costs.